Bifrenaria harrisoniae

Cultural Recommendations: LIGHT: 3000-4500 fc. Since B. harrisoniae is normally found growing in exposed locations on east facing cliffs, full morning sun with afternoon shading is indicated. TEMPERATURE: Summer days average 77-80F (25-27C), while nights average 66-68F (19-20C), producing a diurnal range of 10-12F (6-7C). HUMIDITY: 75-80% throughout the year. WATER: Moderate water is required during the growing season. Care should be taken to keep water off the leaves of new growths. FERTILIZER: A balanced fertilizer mixed at 1/4-1/2 recommended strength should be applied once a week during periods of active growth. After new growth is mature, use a fertilizer with less nitrogen and more phosphorus to allow the new growth to harden before winter and to promote better blooming the following season. To prevent salt buildup during periods of heavier fertilizer applications, the pot should be leached or flushed every month or so. This is accomplished by prewetting the media and then flushing with water equal to twice the volume of the pot. REST PERIOD: Winter days average 70-72F (21-22C), while nights average 58-60F (14-16C), producing a diurnal range of 10-12F (6-7C). Along with the cooler temperatures, water should be reduced to occasional misting or light watering and fertilizer eliminated for about 2 months in winter. Gradually resume normal water and fertilizer applications when new growth starts. Successful growers report that these plants should not be treated too well in winter. They suggest that water and fertilizer applications be restricted to every second or third time that Cattleyas are watered and fed. The pseudobulbs should shrink and even shrivel a bit during the winter rest. In addition, growers indicate that plants should be placed high in the greenhouse to receive maximum light. GROWING MEDIA: B. harrisoniae grows well mounted on slabs or rafts if high humidity can be maintained and sufficient water can be provided. Medium sized fir bark produces good results for most growers who use pots. Successful growers suggest that these plants grow well in a potting mix more like one used for Paphiopedilum than one used with Cattleya. They further indicate that fir bark with a little coarse sphagnum and some perlite added produce excellent results. MISCELLANEOUS NOTES: Because these plants are intolerant of being disturbed once established, repotting should be done only when necessary and then only when new root growth is starting. When dividing, each division should consist of 4-5 pseudobulbs. Growers report that they have never found what initiates blooming, and that some plants never bloom. Whether or not they were providing the conditions indicated above is not known.